Counterbalancing mechanism for embroidering-machines.



Ul ill ULhUJ-JULIL:

GOUNTERBALANGING MECHANISM FOR EMBROIDERING MACHINES.

APPLIOATION FILED 001.14, 1911.

1,073,342, Patented Sept. 16, 1913.

41M 04 mm.

UNITED STATES a'rnn :nrucn.

COUNTERBALANCING MECHANISM FOR EMBROIDERING-MACHINES.

To all whom, it may concern Be it known that I, JOSEPH A. GnoEBLI, a citizen of the United States, and a resident of the city, county, and State of New York, have invented certain new and useful Improvements in Counterbalancing Mechanism for Embroidering-Machines, of which the following is a. specification.

My invention relates to a mechanism for counterbalancing the weight of the tambour frame of an embroidering machine.

It is well known that in large embroidering machines the tambour frame which supports the large sheets of fabric and which is moved at each stitching operation, must be counterbalanced, in order that it may be moved easily and accurately. Various devices have been employed for such purpose which have been more or less successful, but which have inherent disadvant-ages.

In some cases the tambour frame has been counterbalanced by a weight, but it requires considerable force to quickly overcome the inertia of the combined weight of both the tambour frame and the counterbalancing weight. In other cases springs have been employed to counterbalance the tambour frame, but this introduced other difiiculties, because, as the tambour frame was moved in the progress of the formation of the design upon the fabric by the needles, the springs were either contracted or expanded. WVhen the movement of the tambour frame contracted the counterbalancing springs a point was soon reached where they failed to exert suliicient force to fully counterbalance the weight of the tambour frame. But when the tambour frame was moved in a direction which expanded the springs their tension increased until they over balanced the weight of the tambour frame and the force necessary to move the tambour frame therefore increased. In the short movement necessary for a given stitch this was hardly important, but as the tambour frame was moved during the progess of the embroidering of the design upon the fabrics, it threw serious burdens upon the operating source. To overcome this difficulty I provided a compensating system for compensating for the over tension or under tension of the springs, to preserve the equilibrium during the operation of the machine, which is shown in U. S. Letters Patent to me dated November v9, 1897 and numbered Specification of Letters Patent.

Application filed October 14, 1911.

Patented Sept. 16,1913. Serial No. 654,602.

593206. This system required an operating force to operate the compensating mechanism, which force was automatically thrown into and out of action by the movements of the tambour frame. While this system has been in practical operation nevertheless I have found that, while the force necessary to cause the movement of the tambour frame has been made more regular, nevertheless the burden caused by the unequal tension of the springs has been transferred to the device which operates the compensating mechanism and to the latter itself. In one direction (when the springs are contracting) the compensating mechanism has little work to perform, acting more as a regulator: whereas when the springs are distended the work performed by the compensating mechanism is considerable and it increases at a considerable ratio as the frame is moved.

The object of my present invention is to obviate the difficulties of both of the above systems by overcoming the weaknesses of both. In doing so I avoid the great weight of a counterbalancing weight and therefore make it easier to overcome the inertia; and I also avoid the unequal burden on the compensating mechanism. I accomplish these objects in a very simple and eflective manner, by employing a system wherein the amount of contraction and expansion of the spring is reduced. I provide for the uneven action of the springs in expanding and contracting by providing a compensating device which will be self acting-and which does not require the application of an opcrating force to operate it. That is, the compensating device executes its functions automatically as the tambour frame is moved and without any operating force other than the movement of the tambour frame.

A full description of what I deem to be the best embodiment of my invention will follow hereinafter.

In the drawing forming a part of this application the figure is an elevation of an embroidering machine showing my invention applied thereto.

In embroidering machines, of the type with which my present invention deals it is customary to use a parallel motion device for causing the tambour. frame to move in parallelism throughout its length, and I prefer to apply my improved counterbalancing mechanism so that the counterbalancing force is transmitted to the tambour frame through a parallel motion device, and I will describe my invention as so applied, although I do not wish to be understood as limiting my invention to such combined arrangement.

In order to simplify the present case I have shown only the frame structure and tambour frame of an ordinary embroidering machine of the large type, it being understood that any of the well known stitching and allied mechanisms may be used thereon. It may also be said that the tambour frame may be moved in any of the well known ways, either by a hand operated pantograph or an automatic jacquarifl, to execute the movements necessary to the production of the desired embroidered designs.

In the drawing I have shown the principal parts of the stationary frame of an embroidering machine, consisting of the end standards 1 and 2, arranged at opposite ends of the machine and forming the main supports thereof. These standards are shown connected in the usual manner by upper and lower longitudinal beams 3 and at, and a top beam 2.

The tambour frame 5, consists of the usual rectangular frame comprising longitudinal bars 6, and 7, and vertical. connecting bars 8 and 9, rigidly secured together. My invention has to do with the counterbalancing of this frame so that its move ment up or down in its vertical plane of movement may be easily accomplished.

Upon the upper bar 6, of the tambour frame and at opposite ends thereof I have provided yokes 10 and 11, by which the supporting elements act upon the frame. On the top beam 2 of the main frame of the machine I have secured a bracket 12, by means of bolts 13, and this bracket forms a fulcrum point for an angle lever which rocks on a stud let, in the bracket. One arm 15, of this lever has a roller 10, which contacts with the under surface of the top bar of yoke 11, so as to exert a supporting force upon the yoke and permit of the free longitudinal movement of the tambour frame. The other arm 17, of this lever preferably extends upwardly from the fulcrum. Xear the other end of the machine, I have mounted a bracket 18, by means of the bolts 19, and this forms a support for a lever 20, whose hub 21, fulcrums on a stud 22, in the bracket. One arm 23, of this lever is extended horizontally and its end carries a roller 21, which engages the under surface of the top bar of yoke 10, and through this the supporting force is exerted at this end upon the tambour frame. The yoke and roller permit free longitudinal movement of the tambour frame. An arm 25, on the same hub 21, as the arm 23, and forming with the lat ter an elbow lever extends upwardly and is connected with the arm 17, of the first mentioned lever by a strap, cable, or the like 26. This forms the device which is employed for causing the tambour frame to move in parallelism throughout, and is well known in the art.

Extending from the same hub 21, of the angle lever 20, I have provided an arm 27, which is here shown as extending longitudi nally away from the tambour frame. On a bracket 28, bolted to the end standard 1, I have provided a lever 29, which fulcrums on a stud 30, and one arm 31, thereof is extended horizontally, below the arm 27. The arms 27, and 31, have the yokes 32, and 33, fulcrumed to their free ends upon the pins 34, and 35, respectively: and between these two yokes I have connected several coil springs 36, the combined power of which is preferably sufficient to support the weight of the tambour frame. From the hub 37, which carries the arm 31, extends another arm 38, preferably in the opposite direction to the arm 31. To the free end of this arm 38, is connected one end of a coil spring 39, the other end of which is connected to a stationary part of the machine, preferably to the upright part of the frame work and which is here shown connected to a lug 40. The arm 38, is preferably shorter than the .arm 31, so that there will be less expansion and contraction of spring 39, than of springs 36. That is to say, the distance which the point 11, travels away from, and toward, the point 40, at which the spring 39, is secured, will be less than the movement of the end of arm 31, provided my invention in its fullest embodiment is utilized.

In the above described structure the weight of the tambour frame rests upon the rollers 16, 24, and is carried through levers 15, 17, and 23, 25, to the arm 27, which it tends to rock upwardly. This transmits the force of the weight through spiral springs 36, to the arm 31, from which it is transmitted to the spring 39, by the shorter arm 38; and the force is finally borne by the stationary frame where the upper end of spring 39, is connected. The tambour frame is therefore spring supported, or as it is often said, spring counterbalanced. The normal or inactive condition of the parts is preferably that shown in the drawings. \Yhen the tambour frame is moved downwardly, during the operation of the embroidering machine, below the position shown in the drawing, the outer end of arm 27, will move upwardly and the end of arm 38 will move away from the point of support of the spring 39. During the slight movements of the tambour frame or those movements made in going from one part to the other of the same stitch, the move nent will be absorbed by the smaller springs 36,

and as such. movements are slight and rapid the same will have little or no effect upon the larger spring 39, especially where the movement is reduced by the leverage of the lever 29. My purpose is to have these short movements absorbed by the springs 86, without materially effecting the spring 39. But the greater movement of the tambour frame and what I prefer to call the general movement, is caused by the progressive movements of the tambour frame during the progress of the embroidering of the design upon the fabric. That is, the movement from one extreme of the design to the other may be called the general movement while between these are many short movements made for each stitch. The shorter movements are absorbed or lost in the springs 36, but the general movement results in the expansion or contraction of the large spring 39. If the arm 38, moves away from the point of support of the spring 39 during the movement of the tambour frame, the action. causes an expansion of the spring As this spring is expanded its resistance becomes greater and if it were not for compensation its resistance would be so increased that the weight of the tambour frame would no longer be evenly counterbalanced by it and it would require greater force to move the tambour frame as the spring 39, becomes extended. But as the end of the arm 38, to which the spring 39, is

connected, moves in an arc the angle of resistance of the spring 39, upon the lever 29,

changes as the lever swings toward the per 1 pendicular. in the arrangement of parts here shown. If the lever arm 38, were to be moved down until it became parallel with the spring 39. the latter would simply pull against the pivot of lever 29, and would not exert any rocking action on the lever. It is not desirable to reach this extreme, but it will be apparent that between the position shown and the extreme referred to, the angle at which the spring 39, affects the arm 38, gradually changes, so that as the spring is extended and its resistance increased, its turning effect upon lever 29, and therefore 5 its eounterbalancing effect, decreases simultaneously, The leverage and movement of the spring may be so regulated that the difference in the power of the spring when extended may be quite evenly compensated. If the spring has been extended and is then contracted by a reverse movement of the tambour frame, the reverse action takes place and the decreases in the spring tension are compensated for by the changing angle at which the spring effects the lever. It will be understood from this that the compensation is automatic and self acting. but is governed by the movements of the tambour frame. Furthermore it requires no; force of outside power to cause the compenl will have a greater amplitude of than the other during the movements of the .counterbalance the tambour movable tambour Lite combined power of the several springs 36.

My invention not confined to the particular arrangement here shown, but is sus eeptible of change within the scope of the appended claims.

Having described my invention what I claim is 1.An emln'oideriug machine having a movable tambour frame, and means for counterbalancing the tam iiour frame. embodying a plurality of springs arranged to counterbalance the tambour frame and means whereby the weight of the tambour frame will be successively borne by said springs and whereby one of said springs movement tambour frame.

9. An emljn'oidering machine having a. movable tambour frame, and means for counterbalancing the tambour frame, embodying a plurality of springs arranged to frame and means whereby the weight of the tambour frame will be borne by said springs in successive order and whereby at least one of said springs will have a greater amplitude of movement than one upon which the tambour frame weight is subsequently borne. during the movements of the tambour frame.

3. An embroidering machine having a movable tambour frame and means for coimterbalancing the tambour frame, embodying a group of springs arranged to support the tambour frame. a spring of greater power than said first springs. and a lever arranged between the first and second springs whereby the second spring will support the tambour frame through said first springs. said lever being arranged to e pia lize the action of said first and second 1 springs.

l. An embroidering machine having a frame and means for counter-balancing the tambour frame. embodying a group of springs arranged to support the tambour frame, a spring of greater power than said first springs. and a lever arranged between the first and second springs whereby the second spring will support the tambour frame through said first springs, said lever being arranged to equalize the action of said first and second springs. and a stationary support to which said springs are connected.

An embroidering machine having a lmovable tambour frame and means for counter-halancing the same embodying a plurality of springs arranged to counterbalance the tambour frame, a spring of greater power than said first springs, and a lever interposed between said first and second springs adapted to cause said second spring to have a lesser amplitude of movement than said first springs and to equalize the effect of said springs.

6. An embroidering machine having a movable tambour frame and means for counterbalancing the same embodying a plurality of springs arranged to counterbalance the tambour frame, a spring of greater power than said first springs, and a lever interposed between said first and second springs adapted to cause said second spring to have a lesser amplitude of movement than said first springs and to equalize the effect of said springs, and a fixed ultimate point of support to which said springs are connected.

7. An embroidering machine having a movable tambour frame, and means for counterbalancing the same, embodying a plurality of springs arranged whereby the weight of the tambour frame will be successively borne by said springs and whereby one of said springs will have a greater amplitude of movement than another of said springs, a fixed support between which and the tambour frame said springs are connected, and automatic compensating means for preserving uniformity of tension in the counterbalancing springs during the movements of the tambour frame, and adapted to be controlled by the movements of the tambour frame.

8. An embroidering machine having movable tambour frame and means for counterbalancing the same, comprising a fixed support, a pluralitv of springs connected between the tambour frame and said fixed support to receive the weight of the tambour frame in successive relation, a lever having a long and short arm to which said springs are connected whereby one spring will have a greater amplitude of movement than another, said lever and springs being arranged whereby the said lever will automatically preserve equilibrium between said tambour frame and springs as the latter expand and contractduring the movements of the tambo r frame.

9. An embroidering machine having a movable tambour frame, and a counterbalancing device therefor, comprising a spring arranged to counterbalance the tambour frame, a stationary support to which one end of said spring is connected so that one end thereof will be stationarily held, said spring being arranged so that it will be expanded and contracted according to the up and down movements of the tambour frame relative to said fixed support, and a lever having a long and a short arm, with the shorter arm of which the other end of said spring has an unchanging point of connection and to the longer arm of which lever the tambour frame is connected, said lever and spring being arranged whereby the change of leverage between the tambour frame and spring will automatically preserve equilibrium between the tambour frame and spring as the latter expands and contracts during the movements of the tambour frame.

10. An embroidering machine having a movable tambour frame and a counterbalancing device therefor, embodying a lever, a plurality of springs arranged to counterbalance the tambour frame and adapted to operate said lever and a spring connected with said lever and to a stationary support and adapted to support the tambour frame through said first springs and said lever.

11. An embroidering machine having a movable tambour frame, and a counterbalancing device therefor, embodying a lever having a long and a short arm, a plurality of springs arranged to counterbalance the tambour frame, acting on the longer arm of said lever and a spring connected with a shorterarm of said lever and to a stationary support, and adapted to support the tambour frame through said first springs and said lever.

12.An embroidering machine having a movable tambour frame and a counterbalancing device therefor, embodying a plurality of springs arranged to operate in unison and to support the tambour frame, a spring of greater power than said first springs, a fixed support for said last spring, a lever having unequal arms upon the longer arm of which the said first springs are arranged to act and upon the shorter arm of which the said second mentioned spring is arranged to act, said lever and springs being arranged whereby the movement of said lever will automatically compensate for the varying stresses of said second mentioned spring as the latter is contracted or expanded during the movements of the tambour frame.

Signed at the city, county and State of New York, this 11th day of October, 1911.

JOSEPH A. GROEBLI.

Vitnesses HENRY EGLI, AnoLr LEIBUNDGIST.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

